1. Field of the Invention
The present invention relates to a data transmitting/receiving apparatus and a data transmitting/receiving method in which serial communication is performed between a data transmitting device and a data receiving device.
2. Description of the Background Art
A data receiving device may fail to receive data transmitted from a data transmitting device when one or more cycles of delay have occurred between a clock and data as a result of, for example, a delay in a data transmission line between the data transmitting device and the data receiving device, or a delay in the circuit of the data transmitting device or the data receiving device.
In order to inhibit this data reception failure, for example, the control system disclosed in Japanese Laid-Open Patent Publication No. 2012-124716 counts the number of cycles between the transmission end timing of a command and the receiving timing of data for that command, when the command is transmitted to the data transmitting device. Also, the system has a calibration function for adding, by using a plurality of delay elements provided in advance in the circuit, a delay corresponding to the number of cycles, and normal data transfer is performed by the calibration function.
However, with the control system according to Japanese Laid-Open Patent Publication No. 2012-124716, there is a problem that it is necessary to periodically execute a complex sequence of selecting a delay element by calibration, and thus, communication may not be performed immediately when necessary. Another problem is that, when calibration is performed periodically, communication cannot be performed during the calibration, resulting in a reduction in the amount of data transfer.